BMS 107 Vessels and Circulation

Question 0

Define an anastomosis.

Answer 0

Two or more arteries (or veins) converge to supply the same body region.

Question 1

What are the relative O2 and CO2 levels in arteries and veins in systemic vs. pulmonary circulation?

Answer 1

Arteries have more O2, Veins have more CO2 in systemic circulation.

Arteries have more CO2, Veins have more O2 in pulmonary circulation.

Question 2

What are the 3 tunics of blood vessels?

Answer 2

1. Tunic Externa
2. Tunic Media
3. Tunic Interna

Question 3

Where would you find endothelium?

Answer 3

In the tunica interna

Question 4

Which tunic is innervated by sympathetic and parasympathetic input?

Answer 4

Tunica media

Question 5

Compare and contrast arteries and veins (exam only)

Answer 5

Arteries: Small lumendiameter, thick walls, maintains cross-section shape, thickest tunic is tunica media, lots of elastic fibers and collagen, no valves and high blood pressure.

Veins: Large lumendiameter, thin walls, does not maintain cross-section shape, thickest tunic is tunica externa, little of elastic fibers and collagen, has valves and low blood pressure.

Question 6

Name 3 types of vessels that carry blood away from the heart. Which is closest to the heart?

Answer 6

1. Elastic Arteries
2. Muscular Arteries
3. Arterioles

Question 7

What is different about elastic fiber distribution in elastic versus muscular arteries?

Answer 7

Elastic arteries: Elastic fibers are present in all three tunics

Muscular arteries: Elastic fibers are only present in 2 concentric rings between the three tunics (internal elastic lamina & external elastic lamina)

Question 8

At the microscopic level, how would you recognize an arteriole?

Answer 8

They have less than six cell layers of smooth muscle in their tunica media.

Question 9

What are the results of vasoconstriction and vasodilation?

Answer 9

Vasoconstriction (Sympathetic NS): increases blood pressure, increases blood flow to skeletal muscle

Vasodilation (Parasympathetic NS): decreases blood pressure

Question 10

What is the structure and function of capillaries?

Answer 10

Capillaries consist of only a single layer of endothelial cells (tunica interna) and basement membrane. They are the only type of blood vessel where metabolic exchange can occur between blood and cells outside the bloodstream.

Question 11

Name 3 types of capillaries and the features of each.

Answer 11

1. Continuous: most common, no holes in endothelial cells, tight junctions between cells, not leaky
2. Fenestrated: “holes” in endothelial cells, allows fluid exchange between blood and interstitial fluid, basement membrane is continuous
3. Sinusoid: discontinuous capillaries, big gaps between cells, incomplete basement membrane, very leaky

Question 12

Name two things that help venous blood return to the heart.

Answer 12

1. Valves

2. Skeletal muscle pump

Question 13

Where does diapedesis occur?

Answer 13

It occurs through the walls of the postcapillary venules.

Question 14

Which type of vessels hold most of the body’s blood and have low blood pressure?

Answer 14

Veins

Question 15

What is a portal system?

Answer 15

A portal system is a network of veins that drain blood from one area of the body and shunts it to another without traveling to the heart first.

Question 16

How is the hepatic portal vein different from the hepatic vein? How does the liver get oxygen?

Answer 16

The hepatic portal vein shunts blood from the small intestine to the liver. The hepatic vein transports blood from the liver back to the heart. The liver receives oxygenated blood from the hepatic artery.

Question 17

Which two arteries enter the cranium?

Answer 17

Carotid and vertebral arteries

Question 18

Describe the pathway of blood flow out of the brain.

Answer 18

Most venous blood of the cranium drains into the dural venous sinuses and returns through the internal and external jugular vein.